Soil resistant pile fabrics and method of making them



Oct. 29, 1957 E. J. COGOVAN ET AL 2,810,948

SOIL RESISTANT PILE FABRICS AND METHOD OF MAKING THEM Filed June 29, 1955 FIG.|

FI GZv BY 22% 522mm &,

ATTORNEYS United States aren' SOIL RESISTANT FABRICS AND METHOD OF MAKIN G THEM Edward J. Cogovan and Edwin D. Friderici, Amsterdam, N. Y., assignors, by mesne assignments, to Muhasco Industries, Inc., Amsterdam, N. Y., a corporation of New York Application June 29, 1955, Serial No. 518,734

6 Claims. (Cl. 2s 74 This invention relates to the treatment of pile fabrics to cause their pile surfaces to resist permanent soiling and is concerned more particularly with a novel soilresistant pile fabric and a method, by which pile fabrics may be treated to inhibit their tendency to become permanently soiled and discolored. 'Ihe fabrics of the in vention may be of various types, such as floor covering fabrics and drapery and upholstery materials, but, since utilization of the invention in connection with pile fabric carpets and rugs affords special advantages, the application of the invention to that field will be illustrated and described in detail for purposes of explanation.

In'the manufacture of carpeting, it was the practice for many years to utilize pile yarns spun from a coarse grade of wool, since a pile made of such yarns is of good appearance and durability and does not crush readily in use. When a pile made of all-wool yarns becomes dirty, the dirt may ordinarily be removed without diificulty by the usual sweeping, beating, vacuum cleaning, etc. As a result, a carpet pile made of all-wool yarns is not liable to become permanently soiled in use, although long periods of service under heavy, dirty trafiic conditions 'may result in such soiling. More recently, all-wool pile yarns have been displaced to a considerable extent in carpet manufacture by yarns containing vegetable fibers or synthetic fibers. The vegetable fibers, which have been used, include cotton and jute, while the synthetic fibers include those of viscose rayon, acetate rayon, nylon, and polyvinyl chloride and various other well known synthetic resins. The synthetic fibers have usually been employed in blends or mixtures, which frequently contain wool,

while cotton fibers are used in the form of all-cotton yarns, which are commonly employed in sewn tufted fabrics made on sewing machines. Pile yarns spun from blends of wool and synthetic fibers, for example, or made entirely of synthetic fibers or vegetable fibers are satisfactory in many respects, but a carpet pile made of yarns containing 20% or more by weight of at least one vegetable fiber or synthetic fiber has been found to soil rapidly in use and cannot be readily restored to its original condition, so that the soiling and discoloration are likely to become permanent.

The present invention is accordingly directed to the provision of a novel pile fabric, in which the yarns forming the pile have been treated in such a way that the pile resists permanent soiling better than an untreated pile of the same yarns. The new fabric has the desirable resistance to soiling as a result of having been treated by the new method.

For a better understanding of the invention, reference may be made to the accompanying drawing, in which:

Fig. 1 is a view on an enlarged scale and in perspective of one form of the new fabric suitable for use as a floor covering; and

Fig. 2 is a view similar to Fig. 1 of another form of the fabric.

The fabric shown in Fig. 1 is of conventional velvet carpet construction and it includes a backing made up 2,810,948 Patented Oct. 29, 1957 of stufier warps 10, binder warps or fine chains 11 in two sets, and weft yarns 12, 13 lying, respectively, above and below the stuffer warps and bound in place by the binder warps. The pile of the fabric is made up of heavy pile yarns 14, each of which has a portion 14a bound beneath a Weft yarn 12 and another portion 14b projecting upwardly in the form of a pair of tuft legs. In the weaving of the fabric, the pile yarns are raised as loops over pile wires provided with knives and, upon withdrawal of each wire, the loops of pile yarn thereover are cut. This permits the yarns forming the tuft legs to untwist and expand somewhat and the cut ends of the yarns are sheared in finishing operations, so that these ends lie substantially in a plane and together form the pile surface.

The fabric shown in Fig. 2 is of conventional tapestry carpet weave and it includes stutfer warps 15, binder warps or fine chains 16 in two sets, and weft yarns 17, 18 lying, respectively, above and below the stufifer warps and bound in place by the binder warps. The pile of the fabric is formed by heavy pile yarns 19, which have portions 19a anchored in the backing by being passed beneath weft yarns 17. During the weaving, each pile yarn is raised over a non-cutting pile wire to form a loop 20 between each two adjacent weft yarns 17 and, upon removal of the wires, the tuft yarns remain as loops. The tops and the sides of the loops adjacent the tops then form the visible part of the surface of the pile.

The fabric of the invention includes a pile, which has been treated to increase its resistance to permanent soiling and discoloration and the treated pile possesses such resistance because of the presence on the visible portions 'of the yarns forming the pile elements of discrete extremely fine particles of a non-film-forming synthetic resin of the class consisting of polyvinyl chloride, poly.- vinyl acetate, vinyl chloride-vinylidene chloride copolymers, polystyrene, and styrene-butadiene copolymers. Resins which are non-film-forming, as that term is here used, do not form continuous films when colloidal solutions thereof are dried at room temperature, although such resins may be fused by drying at elevated tempera tures. Since the resin is to be present on the pile yarns in discrete particles and carpets are exposed to elevated temperatures in driers in finishing operations, the resin employed should have a softening point such that the particles of resin will not become tacky at ordinary drier temperatures. The temperatures in driers vary considerably, but, if the softening point of the resin is at least about F., the passage through a drier of a carpet with a pile carrying the resin particles is not likely to cause the particles to soften and stick together.

The formation of a coating of discrete particles of resin confined substantially to the outer exposed portions of the yarns forming the elements of a pile may advantageously be efifected by applying a dilute aqueous colloidal solution of the resin to the pile surface by means of'a roller applicator, although spraying and other well known methods may be employed. In the formation of the colloidal solution, emulsifying agents may be employed, but many emulsifying agents hold particles of soil, so that such agents may not be used in the practice of the process. The emulsifying agents found satisfactory are of the anionic type and a typical example of such an agent is sodium lauryl sulfate.

In the application of the colloidal solution, it is employed in dilute form, so that the solids present have a dry weight equal to 5% or less of the weight of the solution with 3% a satisfactory concentration. The roller applicator includes a driven roll dipping into a bath of the solution and the carpet is passed with its pile surface down over the top of the roller with the tips of the pile elements lightly contacting the roller. The fabric is then passed immediately into a drier. By the application of the colloidal solution in the manner described, the solution is kept from penetrating the pile to any considerable extent and, when thecoating is dried, the resin particlesare found substantially onlyon the outer visible portions of the pile. V V f I? V The resins found to be most advantageous :in the .practice of the invention are unplasticizedbut some plasticized resins may .also :be employed and are thus the equivalents .of unplasticized resins for the purpose of the invention. The factor, which determines whether a plasticized resin may :be satisfactorily employed in the practice of. the invention, is the nature of the plasticizer em ployed. Plasticizers of the non-solvent type, which have a .tendency'to exude .after a period of time from the. surface of the resins with which they are used, are objectionable, since such plasticizers exposed at the surface of the resin hold soil particles. The plasticizers, which are acceptable, are those .of the solvent type, which cornflbine chemically with the resin at relatively low temperatures, such'as 212 R, instead'of the normal high, temperatures of plastic curing ranging from about 300 F. :to

400 F. Acceptable plasticizers also do not migrate and are'not lost by volatilization. The plasticizers, which can be employed, vary with the resin and examples of plasticizers suitable for use'wit-h polyvinyl chlorideresin are glycerin and dibutyl phthalate. 'Triere'syl phosphate is a typical plasticizer unsatisfactory for use with poly vinyl chloride in the practice of the method, since it is of. the non-solvent type and exudes from the resin to. be exposedin a position to hold soil particles.

In the application of the co'lloidal'solution of resin, the solid' material deposited ranges from about 0.10 .oz. to abojut'lIO oz. per square yard of pile surface treated. When the coated vfabric issues from the drier, it is desirable as part of the, finishing operations to brush the pile surface to improve 'i'tsappearance and separate yarns, which may have become matted together In the, brush.- ing operation, a part, of the coating of resin particles on the pile'elem'ents is removed. The extent or the removal of particles depends on the weight vof the original coating in that, 'with'a heavier coating, a proportion of the particles may not be firmly adherent to the pile elements. .With' a coating of an initial Weight of about, 1.0 oz. per square yard, the brushing is likely to reduce the weight of the coating to about 0.5 oz, per square'yard, whereas, the initial coating has a weight of about 0.1 QZ- per. sq a the ig of th bru h d coating maybe a o t -075 z- .pe sq ar yard A. oating havng a i t of. a u 00.75 02.1261 square y r xhibit soi l resistance and the resistance-increases with an increase in the Weight .of the coating. Above about 1.0 oz. per square yard, an increase in the weight of the coating does not'appear .to add anything to soil resistance. and the particles of thecoating are likely to dust off. It. may be 'said that, for general purposes, a coating having a final Weight'afterjbrushingof about 0.5 per square yard of pile surface'is satisfactory.

'As anfexample of the treatment of a s'tandarcll-ca'rpet.

in accordance with the method of the invention, the fol l'owingmay be given. j

I Example. .I

The carpet treated was of standard Wilton 'weave with employed was an aqueous solution ofa styrene-'butadiene copolymer having a ratio-of 90%:styreneandbuta diene. This resin is non-film-forming and is sold commercially by Koppers Company, Inc., Pittsburgh, Pa, under the trade-name Dylex K-900-D. The particles in the latex have a size varying from 0.01 to 0.1 microns and the commercial product contains 50%52% solids. In the use of the latex, it was diluted to contain 3% solids on a dry basis and was applied by a roller .coater applicator to the pile surtace of the carpet. The treated carpet passed directly from the-applicator through a drier, the, interior temperature of which 'was The latex was so applied that the dried coating had a weight of about 1.0 oz. per square yard and, after the carpet had issued from the drier, it was brushed and the weight of :the coating. was reduced to about 0.5 oz. per square yard. The carpet was subjected to a standard soil test and was found to possess excellent soil resistance. At the same time, the presence of the resin particles onthe pile elements did not impai the feelof the pile, which was considered to-be substantially as soft as in its original uncoated condition.

We Claim: p 1. vA fabric'having, a pile; resistant to soiling, which comprises a backing and pile yarns having portions .anchored in the backing and, other portions projecting above the backing and form ng thepile elements, and a coating confined substantially to theouter, exposed portions of the pile elements and formed of discrete particles of a .non-filmiorrning; synthetic resin of the. classy consisting of polyvinyl chloride, Polyvinyl acetate, vinyl chloridevjnylidene. chloride .copolymers, polystyrene, and styrenerbutadiene .copolymcrs, the resin having a softening nointv ofat least about 175 F. .and the coating ranging in weight from about 0.075 oz. to about 1.0 oz. .per square yard of pilew surface. 7

2. The tabric of claim 1'. in which, theresin is .unplasfici'zed. V I I 3.. The tune of-cla'imlrium tain atl'e t 20% by weightofat least one fiber of the class consisting of. vegetable fibers and synthetic fibers, 4. -The ,fabric. of claim 1, in which the pile yams in-. elude a substantial amount. of wool forming at least.20% by w ight of he yarns. 5,. A method imparting, soil resistance to the pile of-a fabric, which, comprises, applying ,to the surface of the pile a dilute colloidal water solution, of a .non-film-formi s synthe i rsin'ito form alcoating confined substane =tia lly o he. eutenexpo'sed portions of. the. pile yarns turn ng; the pile elements and y ngthe treated-pile at a e evat t mper tur ,,:the resin bei ,a member at the s an 1g of u i yri yfl ch oride, polyvinyl acetate. v. yl chbnde-vinyliueue, chloride .co nlvmers, pplysty reset and tyrenebutadiene' pclyme s andv having a o t ing point 'Qfja least abou 17.55" Ii-cthe resin .reim inin'g on. the fi ers. "of th y r the term of di crete particles after drying of the coating and ranging in weight irqn jabout, 0.1 oz. to about 1.0 oz. per square yard of" pile surface and the drying exposing, fl e resin to 'ajtemperature below thejsoftening point. of the resin.

6. 'The'method'of'claim 5', in which a part of; the resin is removed from the pile elements by brushing.

References Cited in the file ofthis patent UNITED STATES. PATENIS- I 2,622,307 Cogovanet al.... ;Dec.' 23,1952

ch the pile yarns con- Thackston... :Sept. 15;, 19.4 

5. A METHOD IMPARTING SOIL RESISTANCE TO THE PILE OF A FABRIC, WHICH COMPRISES APPLYING TO THE SURFACE OF THE PILE A DILUTE COLLOIDAL WATER SOLUTION OF A NON-FILM-FORMING SYNTHETIC RESIN TO FORM A COATING CONFINED SUBSTANTIALLY TO THE OUTER, EXPOSED PORTIONS OF THE PILE YARNS FORMING THE PILE ELEMENTS AND DRYING THE TREATED PILE AT AN ELEVATED TEMPERATURE, THE RESIN BEING A MEMBER OF THE CLASS CONSISTING OF POLYVINYL CHLORIDE, POLYVINYL ACETATE, VINYL CHLORIDE-VINYLIDENE CHLORIDE COPOLYMERS, POLYSTYRENE, AND STYRENE-BUTADIENE COPOLYMERS AND HAVING A SOFTENING POINT OF AT LEAST ABOUT 175*F., THE RESIN RE- 